Door structures including one or more horizontally or laterally movable doors are widely used, particularly for outdoor access in residential contruction, hotels and motels. These structures are commonly in the form of units comprising frames and doors fitted to them for preassembly or for assembly on site after the frames have been secured in place in buildings. The doors and frames are usually fabricated of aluminum but sometimes are made of other metal or wood and generally include two glass panel doors, one of which is mounted in a stationary position while the other is laterally movable in the frame. These movable doors, whether of the sliding or rolling type and whether suspended from above or supported below, are referred to herein and in the appended claims as "sliding doors".
While the stationary doors of such structures are readily securable weather tightly in their frames, the sliding doors pose a sealing problem which has long persisted in spite of determined efforts of others skilled in the art to provide a satisfactory solution. In accordance with one such prior attempt, for instance, a second sliding door assembly is used as a sort of storm door so that the wind cannot below directly against the inner door assembly and through the spaces between the sliding door thereof and its frame and supporting structure. This expensive measure even so does not prevent cold air from entering through the open spaces in the two assemblies, there being no seal provided by the second assembly to prevent it.
Another attempt at solving the problem involved the application of a plastic sheet to the inside of the sliding door assembly. The sheet is hung over the assembly in the heating season to keep out cold air, but then it is removed in the warm season so that the sliding door can be used. In addition to the nuisance of attaching and removing the sheet at intervals, this approach has the important disadvantage that it does not solve the problem of dirt and dust penetration into the house through the assembly when the sheet cover is down so the sliding door can be used.